Evacuated bulb mount for piezoelectric crystals



Nov. 7, 1939. L. KAMENAROVIC EVACUATED BULB MOUNT FOR PIEZOELECTRICCRYSTALS Filed March 17, 1958 Patented Nov. 7, 1939 UNITED STATES PATENTEVACUATED BULB MOUNT FOR PIEZOELEC- TRIS CRYSTALS Application March 17,

1938, Serial N0. 196,510

In Italy March 22, 1937 18 Claims.

This invention is directed to improvements in oscillator devices withpiezoelectric crystal suspended in an evacuated bulb, and moreparticularly it includes means for suspending or mounting crystals inevacuated bulbs, which remove the well known objections against theconventional mounts that is their cost and complicated character andalso difficulties found in mounting operations and the unsatisfactorystrength they are provided with.

In accordance with the present invention the suspension or mount of thecrystal supporting electrodes is effected by means of rods which alsoact to connect said electrodes and crystal in circuit and which havetheir roots fast in the bulb press whilst their Opposed ends are engagedin position by means of a transverse insulating sheet whose edges abutagainst the bulb wall.

The present invention also includes features in respect of means formounting the electrodes on support rods and for adjusting the pressureunder which said electrodes are forced against the crystal locatedintermediate them.

Some embodiments of the present invention are shown by Way of example onthe annexed drawing and Figure 1 is a side view of a device inaccordance with the present invention;

Fig. 2 is a side View from left hand as seen in Fig. 1;

Fig. 3 is a section on line 3-3, Figs. 1 and 2;

Fig. 4 is a fragmentary section of an arrangement for mounting one ofthe electrodes on its support rods, said section being to an enlargedscale and on line li of Figs. 2 and 6;

Fig. 5 is a section similar to Fig. 4 on line 5-5 f Figs. 2 and 6;

Fig. 6 is a fragmentary view from left hand of Figs. 4 and 5;

Fig. 7 shows another arrangement of the electrode and crystal supportingrods;

Fig. 8 shows a further arrangement of said rods;

Fig. 9 shows a still further arrangement of the electrode and crystalsupporting rods;

Fig. 10 is a transverse section on line Ill-ill, Fig. 9;

Fig. 11 is a vertical section of a further embodiment;

Fig. 12 is a section on line l"-i2, Fig. 11, and

Fig. 13 is a section showing a modification of Figs. 11 and 12.

In the embodiment of Figs. 1-6 the device includes a bulb l mounted onthe base 2 which carries the pins 3; two pairs of rods 5, 5 and 6, 6

located side by side are fastened in the bulb press i and connected withappropriate ones of said contact pins 3, and they carry the respectiveelectrodes 7 and 8; the top ends of rods 5, 5 and t, 6 are engaged inholes of a flexible and insulating sheet 9, conveniently made of mica,having extensions 9 intended to abut on and resiliently engage with theinternal surface of the bulb wall said sheet ll thus correctlypositioning the rods 5, 5 and 6, 6 and the electrodes carried thereby.

The rods 5, 5 are straight ones and an electrode plate I is mountedthereon by means of sleeves l provided by tongues bent from the edges ofsaid electrode plate; lugs l" extend from said electrode to engage theedges of the crystal l and hold it in correct edgewise position.

The rods 6, 6 are bridge-shaped as shown in Fig. l and they carry asecond electrode 8; at the same time said rods 6, S force the electrode8 against the crystal ill with required pressure, by effect of thespring action they have in view of their above stated bridge shape.

The electrode 8 is mounted on the rods 5, 6 in the manner shown in Figs,4-6; for mounting purposes studs II are welded to the electrode plate 8and extend throughout sleeves i2 inserted through a plate it carried bythe rods 6, 6; said sleeves l2 have a flange 52 at one of their ends andlugs 12' at their opposite ends, said lugs l2 being bent outwardly overthe plate iii to secure said sleeves on said plate; said sleeves 52 arefurther provided with fingers l2" pointing towards the respective sleeveaxis and resiliently engaging the ends of the cooperating studs H.

The position of the studs H with respect to rods 6, 6 and the pressurethey impart to the crystal may thus be easily adjusted, said studs andassociate electrode plate being then fastened in the adjusted positionby soldering each finger.

12" on the cooperating stud ll.

Figs. 7 and 8 illustrate modified constructions of rods 5, and 6, 6.

In Fig. 7 the two pairs of rods diverge at both sides from the middleplane intermediate them Where their root portions are located, and theirtop ends lie in spaced planes the holes in the sheet 9 intended toreceive said top ends of said rods being thus located on two paralleland spaced lines.

In Fig. 8 the rods 5, 5 and 6, ii of both pairs are bridge shaped andtheir ends engaged with the sheet 5; lie in a common plane.

In Figs. 9 and the electrode carried by the rods 5 consists of a plate54 having shoulders I 4' at its sides in which bores are provided toenable said plate to be inserted over the rods 5, 5 which extendthroughout said bores; the internal edges of the shoulders l4 provideabutments cooperating to position the crystal ID in its own plane. Theelectrode 8 and the plate [3 supporting it are supported in the mannerdescribed in connection with Figs. 1-8.

Figs. 11 and 12 illustrate a construction in which all rods 5 and 6 arelocated in a common plane; in this construction a channel or C-shapedelectrode I5 is engaged with the outermost rods 5, 5 of the four rodsystems, the second electrode 8 being carried by the rods 6, 6 locatedintermediate the ones 5, 5; the crystal I0 is engaged between the twoelectrodes 8 and I5 and is held in correct edgewise position by the sideportions l5 of the C-shaped electrode IS.

The electrode 8 has its studs I6 engaged in a plate I! having parallelbores extending therethrough and providing for inserting it over therods 6.

A spring I8 is located intermediate said plate I? and the electrode 8 toforce said electrode 8 against the crystal l0 and a worm-screw I9 isscrewed in the plate I! to provide an adjustable abutment for the springl8 as useful for adjusting the pressure under which the crystal isclamped intermediate the electrodes 8 and IS. The crystal I0 is held inposition in the direction along the rods 5, 5 and 6, 6 by the mica sheet9 at its top edge and by a similar sheet 20 located at its bottom andengaged with the plate H by means of lugs 21, this plate I! being inturn engaged with the sheet 9 by means of additional lugs 2|.

Fig. 13 illustrates an arrangement similar to that of Figs. 11 and 12;in this construction to provide for widening the range of possibleadjustment of the pressure operative on the crystal, the plate I? has anextended screwthreaded protrusion I1 where the screw 19 is engaged; aportion of said protrusion provides a space in which the spring l8extends and thus this spring may have a larger length with respect tothat permissible in the construction of Figs. 11, 12, to make thepressure adjustment more gradual.

In any case the means of this invention provides a safe and resilientmounting for the crystal, said mounting being further simple andinexpensive.

What I claim as my invention and desire to secure by United StatesLetters Patent is:

1. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseinsulating sheet located in said bulb at the end thereof spaced fromsaid press and having its edges abutting on the internal surface of thebulb wall, said sheet cooperating with said rods to position them, anelectrode plate carried by a number of said rods, a second electrodeplate carried by other ones of said rods and a crystal intermediate saidelectrode plates.

2. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate carried byother ones of said rods and a crystal intermediate said electrodeplates.

3. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate carried byother ones of said rods and a crystal intermediate said electrode platessaid rods being of conducting material and acting for connecting saidcrystal in an outer circuit.

4. An evacuated bulb mount fora piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate carried byother ones of said rods and a crystal intermediate said electrode platessaid rods beings resilient and cooperating to force said elecpress, atransverse perforated and insulating sheet located in said bulb at theend thereof spaced from said press and having its edges abutting on theinternal surface of the bulb wall, the ends of said rods extendingthrough and being engaged in the perforations of said sheet, anelectrode plate carried by a number of said rods, a second electrodeplate carried by other ones of said rods and a crystal intermediate saidelectrode plates, said rods cooperating to force said electrode plateson said crystal and to connect it in an outer circuit.

6. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive resilient. and conducting rods having their roots fast inthe bulb press along a common line, a transverse insulating sheetlocated in said bulb at the end thereof spaced from said press saidsheet having perforations and abutting by its edges on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in. said perforations of said sheet and a set of said rodsbeing bent away from the other ones, an electrode plate carried by saidbent rods, a second electrode plate carried by the other ones of saidrods and a crystal intermediate said electrode plates.

7. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive resilient and conducting rods having their roots fast in thebulb press along a common line, a transverse insulating sheet located insaid bulb at the end thereof spaced from said press said sheet havingperforations and abutting by its edges on the internal surface of thebulb wall, the ends of said rods extending through and being engaged insaid perforations of said sheet and said rods providing two sets bentaway from each other, an electrode plate carried by the rods of one ofsaid sets, a second electrode plate carried by the other one of said rodsets and a crystal intermediate said electrode plates.

8. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive resilient and conducting rods having their roots fast in thebulb press along a common line, a transverse insulating sheet located insaid bulb at the end thereof spaced from said press said sheet havingaligned perforations and abutting by its edges on the internal surfaceof the bulb wall, the ends of said rods extending through and beingengaged in said perforations of said sheet, a set of said rods beingbridge-shaped in their portion intermediate said roots and ends thereof,an electrode plate carried by said bridge shaped rods, a secondelectrode plate carried by the other ones of said rods and a crystalintermediate said electrode plates.

9. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive resilient and conducting rods having their roots fast in thebulb press along a common line, a transverse insulating sheet located insaid bulb at the end thereof spaced from said press said sheet havingaligned perforations and abutting by its edges on the internal surfaceof the bulb wall, the ends of said rods extending through and beingengaged in said perforations of said sheet said rods being bridge-shapedin their portion intermediate said roots and ends thereof and providingtwo sets having said bridge-shaped portions extending in opposeddirections away from an intermediate plane containing the rod rootportions, an elec trode plate carried by one of said rod sets, a secondelectrode plate carried by the other one of said rod sets, and a crystalintermediate said electrode plates,

10. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate, means foradjustably supporting said second electrode plate on the other ones ofsaid rods and a crystal intermediate said electrode plates.

11. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate, studsextending from said second electrode plate, a part carried by the otherones of said rods and having means for adjustably supporting said studsand said second electrode plate and a crystal intermediate saidelectrode plates.

An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate, studsextending from said second electrode plate, a part carried by the otherones of said rods and having means for slidably supporting said studsand said second electrode plate, a spring operative between said partand second electrode plate and a crystal intermediate said electrodeplates.

13. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate, studsextending from said second electrode plate, a part carried by the otherones of said rods and having means for slidably supporting said studsand said second electrode plate, an adjusting screw extending throughoutsaid part, a spring operative between said screw and second electrodeplate and a crystal intermediate said electrode plates.

14. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate, studsextending from said second electrode plate, a part carried by the otherones of said rods and having means for slidably supporting said studsand said second electrode plate, said part providing a protrusionextending therefrom away from said second electrode plate and ascrewthreaded bore throughout said protrusion, an ad- J'usting screwengaged in said bore and leaving a space therein in front of said secondelectrode plate, a spring extending into said bore and operative betweensaid screw and second electrode plate and a crystal intermediate saidelectrode plates.

15. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive and co-planar rods having their roots fast in the bulbpress, a transverse perforated and insulating sheet located in said bulbat the end thereof spaced from said press and having its edges abuttingon the internal surface of the bulb Wall the ends of said rods extendingthrough and being engaged in the perforations of said sheet, a C-shapedelectrode plate carried by the side ones of said rods, a part carried bythe intermediate ones of said rods, a second electrode plate carried bysaid part and located within the said C-shaped electrode plate and acrystal intermediate said electrode plates.

16. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at its end spacedfrom said press and having its edges abutting on the internal surface ofthe bulb wall the ends of said rods extending through and being engagedin the perforations of said sheet, an electrode plate engaged with anumber of said rods by means of holes provided in said electrode plateand passed through by the cooperating rods, a part engaged with othersof said rods by means of holes provided in said part and passed throughby the cooperating rods, an electrode plate carried by said part, and acrystal intermediate said electrode plates.

17. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate carried bythe other ones of said rods and a crystal intermediate said electrodeplates one of said electrode plates having edge means for engaging saidcrystal to position it in its own plane.

18. An evacuated bulb mount for a piezoelectric crystal comprisingcoextensive rods having their roots fast in the bulb press, a transverseperforated and insulating sheet located in said bulb at the end thereofspaced from said press and having its edges abutting on the internalsurface of the bulb Wall, the ends of said rods extending through andbeing engaged in the perforations of said sheet, an electrode platecarried by a number of said rods, a second electrode plate carried byother ones of said rods, a crystal intermediate said electrode platesand having an edge portion abutting on said insulating sheet, and asecond insulating sheet engaging an opposite edge portion of saidcrystal and secured LEONE KAMENAROVIC.

